package yangtzedeltasimulatorbackend.component;

import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.exceptions.JWTVerificationException;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import yangtzedeltasimulatorbackend.dao.UserDao;
import yangtzedeltasimulatorbackend.entity.po.User;


import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;
import java.util.Optional;

/**
 * @Description
 * @Auther wyjq
 * @Date 2022/4/6
 **/

@Slf4j
public class CustomInterceptor implements HandlerInterceptor {
    @Autowired
    UserDao userDao;

    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) throws Exception {

        String token = httpServletRequest.getHeader("token");// 从 http 请求头中取出 token

        // 如果不是映射到方法直接通过
        if(!(object instanceof HandlerMethod)){
            return true;
        }
        HandlerMethod handlerMethod=(HandlerMethod)object;
        Method method=handlerMethod.getMethod();


        //检查有没有需要用户权限的注解
        if (method.isAnnotationPresent(LoginRequired.class)) {
            LoginRequired userLoginToken = method.getAnnotation(LoginRequired.class);
            if (userLoginToken.required()) {
//                log.info("someone is verifing :"+method.getName());
                // 执行认证
                if (token == null) {
                    throw new RuntimeException("无token，请重新登录");
                }
                // 获取 token 中的 email
                String email;
                try {
                    email = JWT.decode(token).getAudience().get(0);
                } catch (JWTDecodeException j) {
                    throw new RuntimeException("401");
                }

                //感觉不用
//                Optional<User> userDB = userDao.findByEmail(email);
//                if (!userDB.isPresent()) {
//                    throw new RuntimeException("用户不存在，请重新登录");
//                }
//
//                User user=userDB.get();
                // 验证 token
                JWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256("wangyijie")).build();
                try {
                    jwtVerifier.verify(token);
                } catch (JWTVerificationException e) {
                    throw new RuntimeException("401");
                }
                return true;
            }
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest,
                           HttpServletResponse httpServletResponse,
                           Object o, ModelAndView modelAndView) throws Exception {

    }
    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest,
                                HttpServletResponse httpServletResponse,
                                Object o, Exception e) throws Exception {
    }


}
